Cork is a plant material derived from the bark (suber) of the cork oak (Quercus suber), easily and with great insulation performance. The reason why the cork has these properties is the composition rich in suberin a lipidic substance (fatty acid) that accumulates in the cell wall. The presence of this substance in a first phase, the ingress of pathogens and toxic substances in each cell at a later point in time the passage of nutrients into the cell. The first extraction of cork is usually when the tree reaches between 25 to 30 years, and the extraction takes place in the months of June to August.

These corks, sometimes with considerable thickness, is given the name Virgin and differs substantially from reproduction cork won in the years ahead: the secondary in the second drawing and Amadia referred in subsequent passes or extractions. The Amadia cork is the best quality, so it is the most valued, and which are used to make plugs. From this point, the cork is extracted every nine years.

Cork is a noble raw material, the use of which extends to various applications such as flooring, the thermal and acoustic insulation, in the manufacture of musical instruments, decorative items, shoe components and industry different vehicle segments, beverages, construction, masonry, decorations, among others.

Portugal, with an area of ​​730 hectares of cork oak forests, is responsible for about 50% of the world's cork.